manipulate icon-position of samba-shares on caja-desktop

I know how to manipulate the position of desktop icons with the

set

command

set -t string '/home/user/Schreibtisch/example' 'metadata::cajas-icon-position' '500,500'

But this does not works with samba-shares. I also can't find the samba-shares in

~.local/share/gvfs-metadata/

(where are external drives) How dows one manipulate the Icons of samba-shares on Caja Desktops with gio?